Katarzyna Bilewska

Dr. Katarzyna Bilewska


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
7 July 2021 in Materials
Verified
Journal Article
Open access
PDF file
Damian WojcieszakDamian Wojcieszak
Damian Wojcieszak
Michal MazurMichal Mazur
Michal Mazur
PPPatrycja Pokora
Patrycja Pokora
AWAdriana Joanna Wrona
Adriana Joanna Wrona
KBKatarzyna Bilewska
Katarzyna Bilewska
JDJaroslaw Domaradzki
Jaroslaw Domaradzki
In this work, selected properties of metallic and oxide thin films based on titanium and cobalt were described. Thin-film coatings were prepared using the magnetron sputtering method. The deposition was carried out from sintered targets with different Co-content (2 at.%, 12 at.% and 50 at.%). The relation between the Ti–Co target composition and the Co-content in the metallic and oxide films was examined. There was 15–20% more cobalt in the films than in the target. Moreover, the deposition rate under neutral conditions (in Ar plasma) was even 10-times higher compared to oxidizing Ar:O2 (70:30) plasma. A comprehensive analysis of the structural properties (performed with GIXRD and SEM) revealed the amorphous nature of (Ti,Co)Ox coatings, regardless of the cobalt content in the coating. The fine-grained, homogenous microstructure was observed, where cracks and voids were identified only for films with high Co-content. Optical studies have shown that these films were well transparent (60% ÷ 80%), and the amount of cobalt in the target from which they were sputtered had a significant impact on the decrease in the transparency level, the slight shift of the absorption edge position (from 279 nm to 289 nm) as well as the decrease in their optical band gap energy (from 3.13 eV to 1.71 eV). Electrical studies have shown that in (Ti,Co)Ox thin films, a unipolar memristive-like effect can be observed. The occurrence of such effects has not been reported so far in the case of TiO2 coatings with the addition of Co.

27 May 2022 in Materials
Verified
Journal Article
Open access
PDF file
AWAdriana Joanna Wrona
Adriana Joanna Wrona
MLMarcin Lis
Marcin Lis
KPKrzysztof Pęcak
Krzysztof Pęcak
IKIzabela Kalemba-Rec
Izabela Kalemba-Rec
SDStanislaw Dymek
Stanislaw Dymek
PŚPiotr Śliwiński
Piotr Śliwiński
The aim of this work was to develop a new coating material based on Ni20Cr alloy modified with up to 50%wt. rhenium. The modification was carried out by the mechanical mixing of the base powder and ammonium perrhenate with the subsequent thermoreduction in an H2 atmosphere. The obtained powder consists of a nickel–chromium core surrounded by a rhenium shell. The characterization of the powders—including their microstructure, phase and chemical composition, density, flowability, particle size distribution, and specific surface area—was performed. The influence of plasma current intensity and hydrogen gas flow on in-flight particle temperature and velocity were investigated. The results indicate that there is interdiffusion between the base Ni20Cr and the rhenium shell, resulting in intermediary solid solution(s). The modified powders have a higher specific surface area and a lower flowability, but this does not prevent them from being used as feedstock in plasma spraying. In-flight measurements reveal that increasing the content of rhenium allows for the higher temperature of particles, though it also reduces their speed.